1. Field of the Invention
The present invention relates to a liquid-jetting apparatus which jets liquids.
2. Description of the Related Art
A color ink-jet printer has been hitherto known as a liquid-jetting apparatus for jetting liquids of mutually different types from two types of nozzles, which is provided with an ink-jet head for jetting a color ink or color inks and a black ink with respect to the recording paper or the like. Such an ink-jet printer is sometimes provided with a nozzle cap (suction cap) which is capable of being brought in tight contact with a liquid-jetting surface of an ink-jet head, as a structure for protecting nozzles and/or performing the suction purge to forcibly suck and discharge any viscosity-increased ink and any bubble from the nozzles, as in an ink-jet printer described in US 2007/0296754 (corresponding to Japanese Patent Application Laid-open No. 2007-331268). In addition thereto, such an ink-jet printer is sometimes provided with a structure to perform the gas discharge purge in which the bubble is sucked and discharged from the ink flow passage disposed upstream from the nozzles. Specifically, such an ink-jet printer is sometimes provided with a bubble storage chamber to which the ink is supplied from a cartridge and which is communicated with an ink-jet head, a gas discharge valve which is provided to discharge the bubble from the bubble storage chamber, and a gas discharge cap which is capable of being brought in tight contact with an opening surface of a discharge port to be opened/closed by a gas discharge valve of the bubble storage chamber. The bubble storage chamber and the gas discharge valve are provided for each of the types of the inks. Further, the suction cap and the gas discharge cap are connected to a suction pump via a switching means (changeover means) which is capable of switching the communication between the suction cap and the suction pump and the communication between the gas discharge cap and the suction pump.
In the ink-jet printer as described above, the suction purge is performed by operating the suction pump after performing the switching or changeover so that the suction cap and the suction pump are communicated with each other in a state in which the suction cap is brought in tight contact with the liquid-jetting surface. In this way, the ink, which contains the viscosity-increased ink and/or the bubble, is sucked and discharged from the nozzles into the suction cap. On the other hand, the gas discharge purge is performed by operating the suction pump connected to the suction cap after performing the switching or changeover so that the gas discharge cap and the suction pump are communicated with each other in a state in which the gas discharge valve is opened and the bubble storage chamber is opened in a situation in which the gas discharge cap is brought in tight contact with the opening surface. Accordingly, the bubble can be discharged to the gas discharge cap from the bubble storage chamber which is positioned on the upstream side from the nozzles without allowing the air to be mixed from the nozzles.
The gas discharge valve is opened/closed by an opening/closing member. The opening/closing member is constructed to make contact with a slider, and the gas discharge valve is opened/closed by being moved in the upward-downward direction in accordance with the movement of the slider in one direction. Further, the slider is engaged with a cam groove of a rotary cam, and the slider is moved in one direction parallel to a rotary surface of the rotary cam in accordance with the rotation of the rotary cam. The opening/closing member and the slider are provided distinctly as those for the color inks and those for the black ink respectively. The slider (first gas discharge driving member) for opening/closing the gas discharge valve for the color ink and the slider (second gas discharge driving member) for opening/closing the gas discharge valve for the black ink are engaged with the cam groove of the same rotary cam. That is, when the rotary cam is rotated, the slider is moved in one direction parallel to the rotary surface. In this way, the opening/closing member is moved in the upward-downward direction in accordance with the movement of the slider, and the gas discharge valve is driven and opened/closed.
In the ink-jet printer described in US 2007/0296754, it is noted that the slider for the color ink and the slider for the black ink are engaged with the cam groove of the same rotary cam. Therefore, the two sliders are successively driven by the cam groove in accordance with the rotation of the rotary cam, and the gas discharge valve for the color ink and the gas discharge valve for the black ink are successively opened/closed. In this case, for example, when only the gas discharge purge for the color ink is performed, if the gas discharge valve for the color ink is opened, then the gas discharge valve for the black ink is also opened in some cases in accordance with the rotation of the rotary cam. However, the gas discharge purge is not performed for the black ink. Therefore, when the gas discharge valve for the black ink is opened, the air comes from the discharge port of the bubble storage chamber.
In order that the gas discharge valve for the color ink and the gas discharge valve for the black ink can be selectively opened/closed, the slider for the color ink and the slider for the black ink may be moved by being driven distinctly by means of driving sources such as distinct motors or the like respectively. However, in this case, the cost is increased and the apparatus is large-sized as compared with the case in which one driving source is used.